Understand what you are voting for BEFORE you vote.
Here is a link to updated potential and proposed ballot measures for the 2018 election. Watch for them to update the list of measures certified to appear on the ballot. Discuss them and get to know what they mean and how they affect the state before you head to the booth to cast a vote. There is a lot of word salad and language trickery employed to confuse voters. Don't let them do that to you. Learn about the issues in advance. In fact, learn about them and then go to candidate events and drill them on these issues to see where they stand or if they even understand them.
Also, get to know which of these measures are being pushed, supported, and funded by non-residents of South Dakota. A LOT of those door knockers getting signatures are not even residents of the state. This should trigger all sorts of alarms.